Ophiognomonia castaneae协同板栗褐缘叶枯病病原菌致病作用的研究

Pathogenic Effects of Ophiognomonia castaneae Coordinated with Phomopsis castaneae-mollissimae

为明确板栗新病害褐缘叶枯病病原菌Phomopsis castaneae-mollissimae(Y1)与其共生菌板栗蛇孢日规壳Ophiognomonia castaneae(Y6)的关系,采用在发病不同时期组织分离、定期采样观察、致病性测定及对峙培养等方法进行研究。结果表明,发病初期在褐缘叶枯病病健交界处只分离到Y1,随病斑扩展Y6的分离频率逐渐增加,发病后期Y6的分离频率略高于Y1;Y6的无性型和有性型子实体均生长在病斑上;离体叶片接种Y1易产生病斑,接种Y6很少产生病斑,两菌混合接种比单独接种产生的病斑症状明显且发病速度快,表现出Y1致病力强,Y6致病力弱,Y6具有协同Y1致病的作用;Y6和Y1的营养体表现出明显的完全的亲和力。

The methods such as tissue isolation in different stages,regular sampling observation,pathogenicity identification and confronting incubation were adopted to find out the relation between Phomopsis castaneae- mollissimae（ Y1）,the pathogeny of a new chestnut disease brown margin leaf blight,and Ophiognomonia castaneae（ Y6）,a symbiotic bacteria of Y1. The results showed that at the early stage of brown margin leaf blight,only Y1 was isolated at the junction of diseased and healthy tissue. Along with the extension of lesion spots,the isolation frequency of Y6 increased gradually. At the late stage,the isolation frequency of Y6 exceeded that of Y1 slightly. The anamorph and teleomorph fruit bodies of Y6 both occurred in the lesion spots. Inoculating the 2 fungi to detached leaves respectively,Y1 produced lesion spots easily and Y6 rarely.However,the lesion spot symptom occurred more obviously and the disease developing speed was faster when the detached leaves were inoculated by Y6 combined with Y1 than that inoculated by Y1 or Y6 solo. It showed that Y1 owned the powerful pathogenicity,while Y6 owned the weak pathogenicity,and Y6 and Y1 had the coordinated pathogenic effect. The vegetative body of Y6 and Y1 had the obvious and complete compatibility.